Embodiments of the present invention relate to Software Defined Network (SDN), and more specifically, to reducing broadcast flooding in an SDN of a cloud.
Software Defined Network (SDN) is a network virtualization technology which, by transferring control plane of a router into a controller, separates control plane function from a switching Application Specific Integrated Circuit (switching ASIC) by manner of software, and makes the switching ASIC dedicated to data plane function. Such new network architecture as SDN allows a network administrator to re-plan the network with program in a central controlled manner without changing hardware devices, which not only provides a new method for controlling network traffic, but also offers a good platform for core network and application innovation. Because the SDN possesses features such as powerfulness and flexibility, cloud computing center under current environment has increasingly employed the SDN to dynamically define network topology as needed for communication between nodes.
There are mainly two approaches for using current SDN in data link layer of an Open Systems Interconnection (OSI) Reference Model, one is to use a point to point tunnel, such as Generic Routing Encapsulation (GRE) tunnel adopted by OpenvSwitch, and the other is to use multicast+point to point tunnel, for example, a VxLAN tunnel. No matter which approach is used, if there are a large number of nodes in a network, it often leads to network broadcast storm during network broadcast (e.g., Address Resolution Protocol (ARP)), because there are often a large number of nodes in a cloud computing environment, this tends to be more prominent in a cloud computing environment. For example, as to the GRE tunnel employed by OpenvSwitch in a cloud computing environment, since it is necessary to maintain one tunnel between every two nodes, and a broadcast packet needs to be sent to all the tunnels during network broadcast, it will cause heavy network load, which further leading to network broadcast storm.